Arrow markers do not show with multiple selection or in sparse mode

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Hi,

 

I’ll do my best to be concise since this is my first post here.

 

I’m using Version 9.02 (Build 39951) on macOS.

 

Regarding the issue described in the title, I’ve encountered the following problems when using the arrow marker (drawn in-line):

1. When I select multiple traces and apply the arrow marker, only the first trace is formatted correctly. In the Command Window, I noticed that the subsequent traces have barbSide=0, and if I remove this, they display correctly. However, after a quick query, this issue was supposedly resolved in Igor 6.03 (see here: link).

 

Additionally, if I attempt to change the marker type, the command sometimes doesn’t register. While the changes appear in the “Modify Traces” window and in Command Window, the graph itself remains unchanged.

2. When I try to use “Sparse Markers,” the arrows disappear entirely. This feature works fine with other marker types.

 

Am I missing something or is this a bug?

Thank you for your help.

I made a test case. In Lines and Markers mode, sparse markers and wind barbs seem to work fine. If I select just Markers mode, sparse markers don't work, but my wind barbs are still there.

I see that Arrow Markers (and therefore wind barbs) are very fussy about the number of points in the arrow info wave having the same number of rows as the data trace. Are your traces all the same length?

Can you post your Igor experiment file so that we can inspect it and play with ourselves?

January 28, 2025 at 11:08 am - Permalink

Hi John,

Thank you for your prompt reply. My Igor experiment file is a bit of a mess with data, but I was able to replicate the same behavior described in my first post using a test file with basic sine waves.

In this file, the red sine wave should display with the arrow marker (as you can verify in the “Modify Trace Appearance” window), but it does not appear on the graph.

This issue consistently occurs whenever I have multiple traces and attempt to modify them all at once.

 
testforforum.pxp (6.43 KB)

January 28, 2025 at 10:22 pm - Permalink

I don't know how it came to be, but your second instance of `sin128p` has the optional `arrowMarker` keyword `barbside` set to zero. That means "don't show an arrow head at all".

And I did an experiment that shows me a bug in the Arrow Markers dialog that would lead to that result! This sounds familiar, I think you tried to describe it in your original post, but I was too dense to understand:

Display two traces on a graph

Bring up the Modify Trace Appearance dialog and select both traces

Select Markers mode

Select Arrow Markers, which bring up the Arrow Markers dialog

Turn on the "Draw arrows inline" checkbox

Voila! The generated command is:

ModifyGraph mode=3,arrowMarker(sin128p)={_inline_,1,10,0.5,2},arrowMarker(sin128p#1)={_inline_,1,10,0.5,2,barbSide= 0}

The second command has the `barbside` keyword, and it is set to zero.

I have filed a bug ticket for the bug. In the meantime, the workaround is simply to select one trace, turn on the arrow markers, then select the other trace and turn on the arrow markers. It takes two trips to the Arrow Markers dialog, but you don't have to do it in two trips to the Modify Trace Appearance dialog.

January 29, 2025 at 10:07 am - Permalink

Thanks for checking. The steps are the same I was doing. (I'll be more precise about these in the future.)

Actually my "workaround" is to redo the same command from the Command Window, but manually removing the 

,barbSide= 0

 part. In my example I had only two traces, but with 10 or more is a bit bothersome to set the Arrow Marker for them all one by one.

 

Could you also replicate the arrows disappearing completely when ‘sparse markers’ is turned on?

January 29, 2025 at 06:20 pm - Permalink